Yield:-

Reaction Conditions:

with pyridine;bromine in tetrachloromethane at 80; for 1.5 h;

Steps:

Intermediate 53: 3-bromo-6-methylquinoline

6-Methylquinoline (1.9906 g, 13.903 mmol) was dissolved in 20 mL of carbon tetrachloride. Bromine (0.72 mL, 14 mmol) was added dropwise to the reaction solution and the suspension was heated to reflux (80 °C). Pyridine (1.15 mL, 13.9 mmol) was added while reaction was heating to 80 °C and the reaction was allowed to stir at reflux for 1 .5 hours. The reaction was cooled to room temperature and diluted with dichloromethane. The reaction was washed with water and the organic was dried over sodium sulfate, filtered and concentrated to give a thick brown oil that solidified uponstanding. The crude solid was purified on an 80 g silica gel ISCO column eluting with a very slow gradient: 0% to 15% to 20% ethyl aceate in heptanes to give the desired 3- bromo-6-methylquinoline. ¹ H NMR (400 MHz, CDCI₃) δ ppm 2.52 (s, 3 H) 7.47 (s, 1 H) 7.54 (dd, J=8.59, 1 .95 Hz, 1 H) 7.95 (d, J=8.59 Hz, 1 H) 8.19 (d, J=2.15 Hz, 1 H) 8.81 (d, J=2.34 Hz, 1 H). GCMS = 221 at 2.93 minutes.

References:

WO2013/14569,2013,A1 Location in patent:Page/Page column 55-56